Understanding
Advanced Malware

Detect and Outsmart

Despite substantial investments in numerous security products, organizations continue to be victims of successful malware attacks and data breaches. Today’s sophisticated threats have been engineered to discover and outsmart “advanced malware analysis and detection tools” like firewalls, IPS, and sandbox technologies. These technologies are unable to detect the wide range of evasion techniques described below. So-called “advanced” or “next-generation” malware sandboxes continue to rely on signatures and analyze files only at the application and operating system level, which makes it possible for advanced malware to escape undetected.

Advanced Malware Knows
When It’s in a Sandbox

For years, advanced malware protection has relied on a malware sandbox to block the delivery of malicious files. Sandboxes use virtual machine (VM) technology to analyze suspicious objects. Although VMs resemble a real host, they also insert artifacts into the VM environment for the virtualization to work. These artifacts include additional operating system files and processes, supplementary CPU features, and other components. Sophisticated malware can detect these artifacts, and alter its behavior in order to avoid detection.

Advanced Malware
Evasion Techniques

Advanced malware avoids detection by sandboxes or other security controls by altering its behavior and adopting one or more evasion tactics, such as:

Stalling Delays: The malware simply does nothing for an extended period. Typically, 10 minutes is sufficient for most sandboxes to timeout and assume the object is benign.

User Action Required: The malware avoids doing anything malicious until a user performs a specific action (e.g., a mouse click, pressing a key, opening or closing a file, or exiting the program).

Suspended Activities: The malware postpones these malicious actions while it is operating within a sandbox:

Injection or modification of code within other applications

Establish persistence and download additional code

Move laterally across the network

Connect to its C&C servers

Fragmentation: The malware splits into several components that only execute when it is reassembled.

ROP Evasion: Return-Oriented Programming (ROP) The malware injects functionality into another process without altering the code of that process. This is achieved by modifying the contents of the stack, which is the set of memory addresses that tell the system which segment of code to execute next.

Rootkits: The malware hides malicious code in the lower layers of the operating system where conventional sandbox technology can’t see it.

Fileless Malware

Another advancement criminals have made is malware that doesn’t reside in a file. What makes fileless malware detection so challenging is that these threats reside entirely in memory and remain hidden from most advanced malware detection tools. The most sophisticated versions of fileless malware also are able to completely disappear after reaching their objectives. By operating in such a way that nothing is ever written to disk, and then wiping themselves from memory when done, this ultra-evasive type of malware is extremely difficult to detect.